Let us first read the verses in question:
41:11 Moreover He comprehended in His design the sky, and it had been (as) smoke: He said to it and to the earth: "Come both of you, willingly or unwillingly." They said: "We do come (together), in willing obedience."
21:30 Do not the Unbelievers see that the heavens and the earth were joined together (as one unit of creation), before we clove them asunder? We made from water every living thing. Will they not then believe?
Simply by taking a quick look at the verses, one already begins to see that these verses do not pose a contradiction at all. Furthermore
Assalamualaikum wa rahmatullahi wa barakatuhu, may Allah bless you and your family and have mercy on you and your family in this world and in the Hereafter.
This is quite a long answer as it contains quotations from the Qur'an, Saheeh Ahadeeth, and sayings of well-known scholars, so please kindly read it in full and may Allah increase our understanding through it.
Allah, may He be exalted, says (interpretation of the meaning):
“And He it is Who has created the heavens and the earth in six Days and His Throne was on the water, that He might try you, which of you is the best in deeds” [Hood 11:7]
This is a statement by Allah, may He be glorified and exalted, that His Throne was above the water before He created the heavens and earth and what is in them. Qataadah said: Your Lord, may He be blessed and exalted, is telling you how His creation began before He created the heavens and the earth.
Tafseer al-Tabari, 15/246